| ObjectiveVincent et al. report the first example of a TSHP splice variant in C57BL/6 mice that was expressed in pituitary, thyroid tissues, bone marrow(BM), transcripting begins with 27 nucleotide portion of intron 4 at the 3'end, hence, it lacks the exon 4 but contains all of exon 5 codons. Jeremy S report a TSHβsplice variant in human pituitary, peripheral blood leukocytes (PBL) and thyroid tissues which is similar to mouse TSHβsplice variant, consisting of portions of intron 2 and all of exon 3 codons. It is the first splice variant of TSHP including portions of the intron. Its biology activity has been identified by mean of the assay for cAMP activity in FRTL-5 cells. However, the expression sites and the pathophysiological significance of the TSHβsplice variant remain unclear. In the case of TSHβsplice variant was expressed in pituitary, thyroid tissues, BM, spleen, PBL, Lymph nodes of Balb/c mice, we detect the expression of TSHP splice variant in pituitary, thyroid, BM, spleen tissues in mice which was the model of systemic inflammatory response syndrome (SIRS) prepared by intraperitoneal injection of LPS to determine whether the TSHP splice variant affect the level of circulating thyroid hormone.Methods36 Balb/c mice,7-8 weeks old, half male and femal, were randomly divided into six groups:0 h group,6 h group,12 h group,24 h group,48 h group,72 h group.0 h group:the mice were treated with intraperitoneal injection of NS, the other groups: intraperitoneal injection of LPS (3 mg/kg weight). Then blood samples were collected, RIA and ELIS A were used respectively detect T4 and TSH level in serum.The expression of TSHP splice variant mRNA were detected by reverse-transcriptase PCR in pituitary, thyroid tissues, BM, spleen, PBL and Lymph nodes in Balb/c mice and the amplified gene of thyroid was sequenced. SYBR GREEN real-time PCR was used to detect the level of TSHP splice variant mRNA in different time groups.ResultsCompared to Oh group, other groups serum TT4 were lower (P＜0.01).24 h(9.3283 nmol/L) serum TT4 decreased most significantly,48 h start recovery, up to 72 h(18.696 nmol/L)has not yet returned to normal. The level of TSH had no significant different.RT-PCR showed that TSHβsplice variant mRNA was expressed in pituitary, thyroid tissues, BM, spleen, PBL and Lymph nodes, but native TSHP mRNA was only expressed in pituitary.The level of TSHβsplice variant mRNA in BM at 6 h(0.511027±0.10390)(p< 0.01),12 h (0.36788±0.06024)(p<0.01)and 24 h(0.198357±0.03266)(p<0.01)all decreased compared to 0 h(1.000±0.000), returned to normal at 48 h. The level of TSHβsplice variant mRNA in thyroid tissues at 6 h (10.43319±4.86834)(p< 0.01)increased and other times had no significant different compared to 0 h(1.000±0.000). Both the levels of TSH(3 splice variant and native TSHβin pituitary had no significant different among these times.Conclusions1. TSHβsplice variant mRNA was expressed in pituitary, thyroid tissues, BM, spleen, PBL and Lymph nodes, but native TSHβwas only expressed in pituitary.2. LPS (3 mg/kg weight) depress serum TT4 significantly, but not significantly effect on the level of serum TSH.3. The level of TSHβsplice variant mRNA was up-regulated significantly in thyroid tissues by LPS. But LPS depress TSHβsplice variant mRNA expression in BM. It is suggested that TSHβsplice variant could be involved in immune-endocrine regulation network in the inflammatory responses. Its activity and mechanism need further study. Keywords:TSH Splice variant Balb/c mouse quantitative realtime PCR...
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